The Graphene Sieve That Can Make Seawater Safe To Drink

“Water, water everywhere, but not a drop to drink.” On a blue planet with plenty of salt water and not enough fresh water, this quote has never before rung so true. Water scarcity is predicted to reach crisis levels.

Thankfully, science has stepped up to the plate to save the day! Developed by the researchers at the University of Manchester, the graphene sieve that can make seawater safe to drink. This clever invention is capable of turning the water into fresh, drinkable water. As if this was not impressive enough, the process is also highly cost-effective and efficient.

This new technology, the impact it will have on our society, and the next steps towards the eventual commercialization of this fantastic new invention are at hand.

How It Works

The invention works by incorporating a graphene oxide membrane, which serves as a type of sieve from which it removes salt particles from the water to the point where it becomes potable. Although this function has been long known regarding graphing membranes, no attempts to create such a sieve have ever worked due to issues regarding membrane swelling upon the device being submerged.

The research team at the University of Manchester have been able to produce a device that is successful by covering the walls of the membrane in a resin made of epoxy, which enabled the researchers to be able to control the pore sizes of the membrane.

In order for the membrane to work properly, the four size needs to be so small that it can properly sieve all types of salt matter from the ocean water. The result is a graph fine sees which has an efficiency rate of 97%, according to Nature Nanotechnology.

The lead researcher on the project noted that the Steve functions by allowing water molecules to pass through the membrane individually, which is a function that sodium chloride (i.e. salt) cannot do. He further explains that, in seawater, salt is surrounded by a "shell of water" which is too big for the membrane pores. Essentially, the salt and its surrounding water is simply too big to pass through, but individual water molecules have no problem.

The Societal Impact

At a time when water scarcity is becoming a major problem, this invention is insurmountable. The UN has predicted that about 14% of the entire world population will be affected by water scarcity by the year 2025. Current climate conditions around the world have led to dwindling water resources, especially in heavily populated urban areas.

As a result, the demand for desalination technologies is booming. Currently, modern desalination technologies commonly rely on membranes that are polymer based. Lead researchers working on this new project note that this device is the first time scientists have been able to control the pore size of this type of membrane.

Once it is ready for commercialization and can be deployed to various regions around the world, millions of suffering people and drought-ridden areas will have the access to clean drinking water that they so desperately need. Currently, scientists are faced with a race against time to get this product commercialized, as each passing year more and more cities around the world are finding themselves facing a severe water crisis.

For example in the residents of Cape Town, South Africa have already been limited to 13.2 gallons of water per day. To put this into a higher perspective, the residents of this city are currently limited to two-minute showers, and often have to look for clever ways in which they can reuse and recycle their water. For example, using their bath water to fill up their toilet once they have finished bathing.

The United States is also facing it’s share of crisis, as the countries water reserves have been draining quickly. Los Angeles, Salt Lake City, and Miami are all currently at-risk for finding themselves in the same position as Cape Town. Luckily, advancing desalination technologies are the perfect solution to these evolving problems.

However, despite the positivity surrounding this project, there is still much work that needs to be done in order for this device be incorporated into a scalable industry, particularly in a way that is inexpensive. Before industry is willing to accept the benefits of this product, it is imperative that researchers analyze the long-term effects of membrane exposure to the water elements, including waste and high levels of salinization. For example, it will be imperative for researchers to demonstrate that the membrane will not be clogged over time, which could result in expensive maintenance and repairs having to be conducted on a routine basis.

Ultimately what the research team wants to develop is a final product that will not only serve its intended purpose, but that will be inexpensive and only require minimal energy in order for it to function, which should also be another key selling point for commercialization.

What’s Next?

Down the road, researchers hope that this membrane can first be produced on a smaller scale, which will keep the cost of development down and will enable easy access to countries and regions which do not have the financial means to build a large plant without the end product being compromised.

Additionally, recent developments have taken place within the realm of graphene production scalability. In May 2018, researchers at the Massachusetts Institute of Technology announced that they had developed a new manufacturing process which enables gratifying to be produced in a scalable and cost-efficient way.

This no doubt will have a supremely positive effect on the future of the graphene oxide membrane. Even more exciting is the intentions of the researchers at the Massachusetts Institute of Technology say that they will be working to further the manufacturing process so that it can incorporate any coatings directly onto the graphene material during the manufacturing process. This would include things like polymer and epoxy resins.